Surge arresters of the type named above are typically used for protecting telecommunications devices from transient surges, like those from lightning strikes, for example. Here, by triggering the surge arrester, the outer electrode is short-circuited to the center electrode by means of an electric arc. As soon as the surge goes away, the electric arc is extinguished and the arc gap between the center and outer electrode is again isolated.
In order to maintain the just described protective function even for the loss of a surge arrester, arresters with additional functions can also be equipped. In this connection, mechanisms for protecting the arrester from thermal overloading are known (fail-safe), in which a fusible element made from solder material or also an insulating film is arranged between a spring clip and the outer electrode, which allows the movement of the spring clip, which then bridges and thus short-circuits the arc gap of the arrester between the center electrode and the outer electrode, when the temperature is too high.
Such a surge arrester is known, e.g., from the publication DE 101 34 752. The short-circuit mechanism is triggered by heat in the case of a fault.
One problem to be solved is to present a surge arrester, which is distinguished in the case of a fault by a secure contact between the short-circuiting electrodes.